The justification for describing the Sudeten Germans as Hitler's "fifth column" is fairly simple. In the Czechoslovak general election of 1935 around 60 percent of the country's 3 million ethnic Germans voted in favour of German nationalist parties, dominated by Konrad Henlein's Sudeten German Party, which openly sympathised with Nazi Germany. In local elections three years later this figure was no less than 90 percent, and by this time - in the wake of the German Anschluss with Austria - Henlein was openly and vocally calling for Sudeten Germans to be allowed to go "heim ins Reich", to join the Nazi German homeland.

Under the Munich Agreement of September 1938 the major world powers gave Henlein and Hitler what they wanted. To the consternation of the Czechoslovak government, all the border areas with a majority German population were handed over to Hitler. Most Sudeten Germans welcomed Hitler with open arms. This is how the American journalist, William Shirer, who entered the Sudetenland with German troops, described that moment:

Photo: Bundesarchiv, Bild 183-H13160 / CC-BY-SA / Creative Commons 3.0"In five minutes we reached the Czech customs house. It was deserted, but outside delirious Sudeten Germans had already started to erect a triumphal arch of telephone poles, decorated with pine branches, and over which they had already scrawled a sign: "Sudetenland Welcomes its Liberators." And then, from across the fields between the woods, the peasants started to emerge, jumping up into the air, raising their hands in the Nazi salute and screaming at the top of their voices "Heil Hitler!"

Six months later, the Nazis occupied the rest of the Czech lands. During the occupation many of the officials, administrators, informers and spies of the Nazi Protectorate were also Sudeten Germans. 150 000 Czechs, many of them Jewish, died during the occupation and at the end of the war, the depth of Czech bitterness was understandable.

These are the facts, but the history is more complicated.

Large scale German settlement began during the reign of the king Premysl Otakar II in the 13th century. He invited Germans to settle in the largely uninhabited and heavily forested border areas. They maintained their German language and culture for over 700 years, and in time came to make up no less than a third of the population of Bohemia and Moravia. The Czech and German-speaking inhabitants generally lived peacefully together.

The seeds for the later Czech-German tragedy were sown at the time of the Thirty Years War in the 17th century. The defeat of the Czech protestant aristocracy in 1620, was followed by three centuries of domination by the German language and culture under the Austro-Hungarian Empire. The German speakers of Bohemia and Moravia enjoyed privileged status.

But even with the spectacular revival of Czech national culture in the 19th century, it was only with the First World War, as it became clear that the Austro-Hungarian Empire was falling apart at the seams, that Czech politicians or intellectuals began seriously to dream of complete independence from Vienna. From exile in the United States, Tomas Garrigue Masaryk and his younger colleague Edvard Benes, who later became the first and second Czechoslovak presidents, began to lay the foundations for an independent Czech state.

Czechoslovakia, founded on the 28th October 1918 was a modern democratic state on the American model, but this combined with a very strong awareness of Czech national interests. The very composition of the state - a more or less artificial union between the Czechs and Slovaks - offered a guarantee that the three million German speakers would remain a weak minority in a Slav- or more accurately Czech-dominated state. In the wake of the World War, the Sudeten Germans were given no say in the matter. The historian Katrin Bock has made a study of the period.

"Most of the Germans living in Bohemia and Moravia didn't want to belong to the Czechoslovakian state after the First World War, because they were used to being part of the Austrian monarchy and they didn't suddenly want to be a minority in a state of Czechs and Slovaks, and they didn't like it, that the new constitution was worked out without them. A lot of the Germans felt that the new constitution didn't fulfill what the Czechs had promised in Paris, because they thought there were not enough minority rights in it. (But they did gradually get used to being Czehoslovak citizens.) They took part in the first elections of 1920, and six years later in 1926 the first German was a minister and the first German party was part of the government, so they just got used to feeling themselves as Czechoslovakian citizens."

But this period was short-lived. In the 1930s the great depression hit the heavily industrialized German-speaking regions more than any other part of the country. Unemployment rose to over twice the level seen in Czech-speaking areas, and Sudeten German nationalists accused the Czech authorities in Prague of ignoring the interests of the border regions.

And in 1933 Hitler came to power in Germany. His territorial ambitions were no secret and he fanned discontent among the Sudeten Germans. The German press and radio stations broadcast viciously anti-Czech propaganda, frightening Sudeten Germans with invented stories of Czech atrocities, at the same time promising an economic golden age if only they were to join the Reich. Here is a rare recording of Radio Prague's English broadcasts in 1938, trying to counter the Nazi propaganda:

"Once again tonight we must perform the distasteful task of refuting further invented reports broadcast by the German wireless stations. It is not true that the rectors and deans of German universities were forced at the point of a gun to sign a declaration of loyalty to the state. This absurd allegation was denied by the rectors and deans themselves in a statement made today, denying that any pressure whatsoever was used against them."

The Czech journalist Milena Jesenska, who later died in the Nazi concentration camp of Ravensbruck, spent a great deal of time in the Sudetenland as the tensions rose in the mid 1930s. In a series of articles, she pointed to the pressures that the Nazis were putting on ordinary Sudeten Germans to conform, as vigilante groups of Nazi youths patrolled the streets. In May 1938 she wrote:

"Many people, very many, have succumbed, and have raised their right hand in the Hitler salute. I know of one 48 year old worker - a Christian Democrat - who was given an ultimatum. Either join the party, or don't bother to come to work tomorrow. He refused to join. On the 3rd May he lost his job and on the 4th he hanged himself."

The Nazi Occupation of Czechoslovakia, photo: Wikimedia Commons / PD
When Hitler annexed the Sudetenland in September 1938, the many thousands of Czechs who fled inland from the occupied areas were also accompanied by thousands of Sudeten Germans. These were Social Democrats, Communists or Jews, who knew that they would be sent to the camps under the new Nazi regime. Milena Jesenska again:

"Democratic Germans are coming from the border regions. I don't need to tell you what they are fleeing, and what awaits them should they be made to go back. They include women who have no idea where their husbands are, and when or where they will see them again. There are even unaccompanied children."

After annexing the Sudetenland, Hitler cynically seized the rest of Bohemia and Moravia in March 1939. The small Sudeten German anti-Hitler resistance moved to London, at the same time as President Benes's government also began to work from exile in Britain. But Benes was careful to avoid his German-speaking compatriots. In the wake of Munich, he had one great fear: although he was convinced of German defeat, he was terrified that the border changes established by Munich might stay in place. eHHHe He was determined that Czechoslovakia should not only keep its pre-war borders but also get rid of its German minority once and for all. This was part of the new world order that he spoke of in a speech in Stoke on Trent in 1942.

"And we must all stand together in order to prepare - after victory has been achieved - a peace in Europe over which we could already today solemnly declare that all that we are passing through now, today in this war, will never happen again."

It was in this spirit that President Benes issued the decrees allowing the expulsion of over two million ethnic Germans from Czechoslovakia and the confiscation of their property after the war. In today's terms this sounds very much like "ethnic cleansing", but after the unthinkable cruelties of the occupation, Benes's sentiments are perhaps not hard to understand.

Several thousand Sudeten Germans died during the expulsions between 1945 and 1947. By some estimates the number amounts to tens of thousands.

So were the Sudeten Germans Hitler's "fifth column" as Prime Minister Zeman suggests? In 1938 Milena Jesenska reckoned that one third of those who had joined Henlein's party were convinced Nazis, a third joined in the hope of escaping poverty and the remaining third out of fear. We shall never know what was going through those people's minds at that time, but it is clear that Mr Zeman's claim is no more than a partial truth.